High-grade nickel-steel alloys and related materials are typically used for the manufacture of aircraft engine parts and other high-stress, high-temperature applications. These materials are necessarily difficult to cut or machine and tend to be expensive so it is desirable that waste should be minimized. Cutting of these high-strength alloys usually requires the use of abrasive cut-off wheels that are consumed in the cutting process, posing a potential air pollution hazard for the machine operator and those nearby. It is often desirable to divide a piece of forging stock of such material into nearly identical size ring sections for further forging or machining. If the ring sections can be identically sized and a minimum of material lost in the cutting, the process will be more economical.
Various types of machines have been developed for precision cutting of rings. Examples include: U.S. Pat. No. 4,052,822 issued to Obear is directed to a cut-off machine that employs a pair of abrasive cut-off wheels, the first of a larger diameter, and the second being a used, worn-down wheel of a smaller diameter. The second, smaller wheel, which is necessarily more rigid than a larger wheel, is used to produce an accurate scoring cut to align the larger cut-off wheel.
U.S. Pat. No. 3,877,180 issued to Brecker, is directed to a hydraulic, feedback-controlled system for directing an abrasive cut-off wheel. A first hydraulic system supplies torque to the cut-off wheel, while a second hydraulic system urges the cut-off wheel toward the workpiece. A feedback system balances the pressure applied to urge the cut-off wheel toward the workpiece with the system supplying torque to the wheel so that a constant rotational cutting speed may be maintained.
U.S. Pat. No. 4,802,311, issued to Schreder et al. is directed to a method of grinding rotary workpieces that is automatic and has accurate calibration of work monitoring. The method employs a surface grinding apparatus that is moved horizontally and vertically about a rotating workpiece.
U.S. Pat. No. 5,595,525 issued to Hayashi et al. is directed to a numerically controlled grinding machine. In this invention one grinding wheel grinds a workpiece having a plurality of portions to be ground with the machine enabling an operator to easily and correctly input grinding data and to modify the data in response to grinding conditions displayed to the operator.
U.S. Pat. No. Re. 33,904 issued to Rudy et al. is directed to a method and apparatus for automatically cutting food products to predetermined weight or shape. As the food products move along a conveyor, a camera provides a programmed computer with dimensional data and thus the computer is able to control the operation of the cutters in order to cut the material into portions of equal weight.
Finally, U.S. Pat. No. 4,831,907 issued to Gnann describes is directed to a method and apparatus for checking performance of a cut-off operation on automatic lathes for working bar material or the like.
While other inventions exist having features desirable for efficient cutting of rings from forging stocks the above-described designs for cut-off machinery and related features are typical of those encountered in the prior art.
It is an objective of the present invention to provide for cutting of rings of precisely described dimensions from forging stocks of high-strength alloys. It is a further objective to provide such precision cutting with a minimum of waste. It is yet a further objective to permit the safe and economical cutting of rings from both cylindrical forging stock and forging stock of irregular cross-section. It is yet another objective of the invention to provide a means for efficiently recycling the waste material produced by the cutting process while minimizing any pollution produced by the process. It is still another objective to provide a means to maintain a constant surface speed of the cutting means with respect to the forging stock despite wear of the cutting means. It is a still further objective of the invention to control the temperature of the cutting process to maximize cutting speed while minimizing heat distortion and wear of the cutting means. Finally, it is an objective of the invention to provide the above-described capabilities in an inexpensive and durable machine, which is capable of extended duty cycles, and that may be easily repaired and maintained.
While some of the objectives of the present invention are satisfied by features disclosed in the prior art, none of the inventions found include all of the requirements identified.